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Platelet Function Test: Platelet Aggregation Profile (with or without ADP stimulation)

Published: August 9, 2026Updated: August 16, 2026

This test measures how well your platelets stick together to stop bleeding. It helps doctors check if your platelets work normally, especially after injury or surgery.

Quick summary

["Understanding how your platelets function can help identify bleeding risks or clotting disorders."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
82799-8
Short code
Spatial clot growth Pnl PPP
Synonyms
Spatial clot growth Pnl PPP
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
coag
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Is Done

Doctors may order this test if you have unexplained bruising, bleeding, or if you’re taking blood-thinning medications. It’s also used before surgeries or procedures that could affect bleeding.

How the Test Works

A small sample of your blood is mixed with special chemicals (like ADP) to trigger platelet clumping. The test measures how quickly and strongly platelets stick together, which helps assess their function.

Sample Collection

Blood is drawn from a vein, usually in your arm. The sample is sent to a lab where it’s tested immediately or stored for later analysis.

What to Expect Before the Test

No special preparation is needed, but inform your doctor about any medications (like blood thinners) or recent injuries that could affect results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

This test is critical for diagnosing bleeding disorders, platelet dysfunction, or clotting issues. Abnormal results may indicate conditions like von Willebrand disease, thrombocytopenia, or aspirin-related platelet dysfunction.

Short name

Platelet Aggregation Study

Frequently asked questions

What are the most common reasons doctors order this test?
Doctors often order it to check bleeding risks before surgery, evaluate unexplained bruising or bleeding, or monitor medications that affect platelet function.
How long does it take to get results?
Results are typically available within 24 hours, depending on lab processing times.
Can I eat or drink before this test?
No special diet is required, but let your doctor know if you’re taking blood-thinning medications or have recent injuries.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy